Its recommended to grease your outer bearings every 18 - 20 hours or at a minimum once a year if using only a few hours per year or before any hard freeze to press out any water from the summer/fall use in northern climates. Your inner bearings need to be greased every 25 - 30 hours or after any time you powerwash the interior or get water inside the unit. 4 pumps of grease per bearing using a hand grease pump. Do not use a pneumatic grease gun on any of the Argo bearings as the high pressure could pop the seals off the bearings.